Artificial Insemination – Teaching old dogs new tricks
As many readers would know, Department of Agriculture and Fisheries (DAF) Beef Extension Officer, Matt Brown, is also a business partner in a beef cattle herd near Rockhampton. As well as his extensive experience in extension, Matt has learnt a lot from his private business and reflects on these experiences in this article, particularly on the topic of artificial insemination programs he has developed over the last two decades.
Attending Emerald Agricultural College in the early 1990’s opened many doors to me as a teenager, giving me skills that I have used for many years. One such skill was pregnancy testing, which has been an essential tool that I have used in our beef business, and another was learning to artificially inseminate (AI). I have had an interest in breeding cattle my entire life (some people have seen it as an obsession) and I have thoroughly enjoyed using AI to experiment with different breeds and markets.
After leaving ag college, I got the bug to break in young horses and train working dogs. I used to love saddling up a horse twice a day, checking the females in the AI program with a trusty hound by my side. It was a great education for the horses bringing in the cattle to be inseminated, over several months.
Time marches on and unfortunately the horses have left our operation, but I still have a handy hound and the same passion for breeding cattle.
Practices have changed in the last 20 years in the AI field, but something that has remained consistent is the need to plan. There are many logistics to be considered when entering an AI program that should not be entered into on a whim.
Plan, plan and plan some more
AI programs can be expensive so you must have a purpose to enter into them. AI is a great tool to introduce genetics into the herd without buying a bull. The first step is to establish breeding objectives which are the purpose or reason for introducing the genetics into your herd. Breeding objectives should be determined for all cattle breeding operations regardless of if they are using AI or not.
Points to consider when creating your breeding objectives include:
- Current herd performance – fertility (calving and weaning percentages) and growth rates achieved by your herd. This includes traits that you are looking for in the bull’s semen that you use. The main points that you need to consider when selecting on traits are:
- Are the traits measurable? For example, weight gain.
- Are the traits heritable? For example, fertility is a highly heritable trait.
- Is there variation within the trait? Do not select animals that are extreme in a trait, such as extremely tall or extremely small.
- Is the trait of economic importance? For example, the intervals between calves that the bull’s mother has influences her lifetime productivity.
- Requirements of your customer, for example, seedstock or commercial cattle production.
- Environmental constraints of your property – are you breeding the right type of animal for your environment?
Once the breeding objectives are identified, the next step is to determine which class of females to use in the program.
Maiden heifers are a popular choice for AI programs. They are less likely to have sexually transmitted diseases, and if on a rising plain of nutrition, can cycle regularly to aid conception. If using females with calves, the calves need to be a minimum of six weeks old and females need to be in good body condition. The same principles apply to all breeding operations, females need to be on a rising plain of nutrition with a good body condition score to achieve high conception rates.
Preparation of the mob for the AI program should start 12 months before the AI program is to take place. This will ensure that the mob is on a rising plain of nutrition, and more importantly, bulls are kept away to prevent any accidental pregnancies. It is also important to make sure the mob is vaccinated for diseases, such as leptospirosis, 5 in 1, botulism, and the pestivirus status is known before the program begins as a means of ensuring the conception rates are as high as possible. Remember that when planning the AI program, it is really important to ensure that the mob will calve at the optimal time of the year. It is ideal for calves to be born when the pasture quality is highest as this will allow good calf growth (through receiving adequate milk supply) and will ensure females will cycle again with the calf at foot.
Calmer cattle conceive easier than stirry animals. Ensure that the females that enter the program are quiet as you will be spending a lot of time with them and they will need to be handled regularly.
Functional yards and facilities are also very important, especially as the mob may need to go through the race and vet crush several times during the program. Many times I have had to AI cattle in less than desirable facilities which can make the whole situation stressful and dangerous to both animal and operator.
Many producers learn how to AI their herds themselves, while others will pay technicians to manage and conduct the program on their behalf. For our herd, I decided that I wanted to do the AI work myself and did a refresher course several years after I was initially taught. If producers decide to do the inseminating themselves, they need to ensure that they have the appropriate equipment such as:
- An appropriate sized AI gun (there are two different sizes of semen straws)
- Preg testing gloves
- Thaw unit
- Breeding calendar for writing down dates, sires, and other important notes
- Semen inventory list
- Filled AI tank
- Shaded preparation area crushside (semen is UV sensitive)
When I first started down the AI road, my father purchased an AI tank to store the straws of semen. I christened it ‘Alice’ and we had many adventures. Alice was second-hand and a big mistake we made, that could have rendered our investment worthless, was that we never got her checked for leakage of the liquid nitrogen. Such a check would have ensured that the semen she stored would remain frozen. Thankfully she was a sound tank that served us very well for many years. If considering purchasing a second-hand tank, make sure that it is tested for leakage before the precious semen is stored in it—the last thing you want is for the semen to defrost as it will be ruined. This should not be an issue if you purchase a brand new tank.
Considering how you transport your AI tank is also important. My father had a very cavalier attitude to Alice’s transport requirements and one time placed her in the back of our Toyota ute and proceeded to drive at a break-neck speed, which made her cap come open and the bung that holds the nitrogen in place, fly out. Thankfully, disaster was averted, the bung was found, and no harm was done. Consequently, after that debacle, Alice was buckled into the front seat of my car to accompany me to our AI jobs. Looking back, that really wasn’t the most sensible move either, as if we had crashed, Alice could have tipped all the liquid nitrogen all over myself. The old Alice has been retired and the new Alice now travels securely in the back of the vehicle where she is comfortable and safe and compliant with workplace health and safety requirements.
The liquid nitrogen in AI tanks needs to be checked regularly when storing semen. Alice gets topped up every six weeks.
Selecting the semen
Producers need to use the same skills when selecting semen for AI programs that they use when buying bulls. Each bull’s semen that is purchased is driving the direction of your herd and your profitability for up to 10 years into the future if his daughters are retained in the herd.
Semen goes through several tests before it can be frozen in Australia and there is a huge range of breeds available for purchase. There are certain standards that the semen must meet before it can be processed for commercial sale within Australia and specific criteria to meet export requirements. However, semen that is sourced internationally may not have undergone the same quality assessments. It may even pay to buy a few extra straws to get tested before it is used in an AI program, if purchased from international bulls. Semen can vary significantly in price depending upon the bull and breed.
When considering semen, make use of EBVs (Estimated Breeding Values) if available. EBVs have the following components:
- traits are expressed in the unit of measurement e.g. kg, cm, days
- they can be positive, negative or zero
- genetic progress shifts the average EBV for each trait within each breed, each year
- the base (0) for a trait is set at a particular time for each breed
- EBVs cannot be compared between breeds
- each trait has an accuracy value (%).
Many people don’t realise that AI has a generally accepted success rate of up to 60-75%. It is recommended to run a mop up bull with the mob after the program has been completed to maximise pregnancies. It is a good idea to ensure that the mop up bull is up to date with vaccinations and is free of any disease.
Reflections from an old dog
Huge progress has been made over the years in AI program structure. When I first started, I used to monitor the mob and inseminate on natural heat cycles. This could go over a three-month period. Time wasn’t a factor back then and I found it relaxing checking the mob twice a day. However, those days are gone, and time is now important. Synchronised and fixed time AI programs are now available for those of us who are time poor. Also, there are a lot of specialised people available who can help plan or manage the program for you. These people provide wonderful advice and are very helpful.
I get a great sense of satisfaction when viewing the calves that have been produced through an AI program that I have managed. As mentioned previously, AI is a great tool to bring specific genetics into your herd that may otherwise be out of economic reach. If you are considering entering into an AI program, ensure that you have extensively planned the program to get the highest conception rates possible.